Article II, section 3 of the Constitution says that the president shall "receive Ambassadors and other public Ministers." In our textbook, we write:
According to a generally accepted interpretation, this power means that the president decides whether to recognize foreign governments after a revolution or regime change. More generally, this power to shape the content of talks with foreign diplomatsit implies the power to define U.S. policy and run the day-to-day business of foreign affairs. Unlike Congress, the chief executive sits atop a bureaucracy that is responsible for defense and foreign affairs, and so has ready access to information. Unlike Congress, a single leader can act with dispatch, consistency, and secrecy, especially in a crisis.Findlaw notes:
Ambassadors and other public ministers'' embraces not only ''all possible diplomatic agents which any foreign power may accredit to the United States,'' 569 but also, as a practical construction of the Constitution, all foreign consular agents, who therefore may not exercise their functions in the United States without an exequatur from the President. 570 The power to ''receive'' ambassadors, et cetera, includes, moreover, the right to refuse to receive them, to request their recall, to dismiss them, and to determine their eligibility under our laws. 571 Furthermore, this power makes the President the sole mouthpiece of the nation in its dealing with other nations.But there are certain things that Congress can do. Buzzfeed reports:
"I anticipate I’ll be the chairman of the Western Hemisphere subcommittee on the Foreign Relations Committee” in the new Congress, Florida Sen. Marco Rubio said in a press conference hours after the release of American prisoner Alan Gross from a Cuban prison was announced along with the administration’s plans to normalize relations with Cuba, including opening an embassy there.Amanda Taub writes at Vox:
“I anticipate we’re going to have a very interesting couple of years discussing how you’re going to get an ambassador nominated and how you’ll get an embassy funded,” Rubio, an ardent opponent of lifting the Cuban embargo, said.
...A Senate Democratic appropriations aide acknowledged the administration also can’t simply repurpose funds that have already been appropriated to the State Department, explaining, “Any reprogramming must be approved by the Appropriations Committee,” which, starting in January, will be controlled by Republicans.
Legally, the President cannot unilaterally lift the embargo. Many of the restrictions are codified in legislation that only Congress can change. However, the President does have the authority to make sweeping changes how the embargo works in practice. If he chooses to exercise his full executive authority, there may be little left of the embargo for Congress to repeal...[The] President can make sanctions less restrictive in practice by exercising his licensing authority under the current laws. The executive branch has the authority under current law to issue licenses that permit US citizens and corporations to do business with Cuba, travel there, and send money to family members there. The president isn't making licenses for those activities universally available, but he will make them easier to get.